Test Data for a Trading or Analytics System (OHLCV)

You need rows that look like price bars to test a pipeline, but you should not use real client or licensed data. Here is how to make test data, and where its limits are.

Open the Schema Data Generator

Quant and trading engineering teams build pipelines that load, validate and display price bars, and these need test data. Using real data brings licence terms, confidentiality and storage questions. Test data avoids these and lets you create exactly the cases you want to check.

The Schema Data Generator takes a CREATE TABLE statement, for example a table with a symbol, a timestamp, open, high, low, close and volume, and creates up to 500,000 rows that fit every column type and rule. You can download CSV, JSON, Parquet or Excel and load it into your test system. This checks the shape of the work: column types, row counts, file handling and the speed of a load.

Be clear about the limits. Random values that fit a column type are not a market. The rows will not have realistic trends, volatility, gaps or the relationship that the high is at least the open and close. Do not use this data to test a trading strategy or to draw conclusions about performance. Add checks of your own, such as high not below low, and see whether your validation catches a deliberately broken row.

If you already have a real file that you are allowed to share internally, the Synthetic Data Generator can make new rows that follow its ranges and shares. Read its limits first: it follows the patterns it finds and does not copy a real row, but the quality of the result depends on your input and you should compare it with the original.

Label test files clearly, for example with a test_ prefix, so they are never mistaken for real data. This article covers test data only and is not investment advice.

Open the Schema Data Generator

Related tool pages

  • Generate Data from CREATE TABLE: Paste a CREATE TABLE and get up to 500,000 rows of realistic test data that fit every column type and rule. Free, and runs in your browser.
  • JSON Schema Data Generator: Paste a JSON Schema and generate realistic sample data that follows it: formats, enums, ranges and nested objects. Free, in your browser.

How to use the Schema Data Generator: step by step

  1. Write or paste a CREATE TABLE for your price bars.
  2. Open the Schema Data Generator and choose the number of rows.
  3. Download CSV or Parquet and load it into the system you are testing.
  4. Add a few broken rows on purpose and confirm your checks catch them.

When to use the Schema Data Generator

  • Test a data loader or a dashboard
  • Check file handling for a large table
  • Create deliberately bad rows to test validation
  • Share a sample without sharing real data

Example

Input: CREATE TABLE users (id INT PRIMARY KEY, email VARCHAR(100), age INT);

Output: 1, ada.chen7@example.com, 34

Frequently asked questions

Which databases are supported?

CREATE TABLE from PostgreSQL, MySQL, SQL Server, Oracle and SQLite. Comments, quotes and schema names are handled.

Are foreign keys checked?

No. A foreign key column gets a number from 1 to 100, so load the parent table with ids 1 to 100 first.

Which JSON Schema versions work?

Draft 7 and newer for the common keywords listed above. Unknown keywords are ignored.

Is the data real?

No. It is random and fictional, so it is safe to share.

Tip: Prefix test files with test_ so nobody mistakes them for real market data.